Holding unit for an elastic tensioner



Oct. 6, 1959 M. e. FERNANDEZ 2,907,239

HOLDING UNIT FOR AN ELASTIC TENSIONER Filed April 15, use

Manuel 6. Fernandez 1N VEN TOR.

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United States Patent This invention relates in general to new and useful improvements in attachments for sewing machines, and more specifically to a holding unit for an elastic tensioner.

In the making of clothing there are many types of clothes which are provided with elastic sewn into the waist or other portions thereof. In order that the elastic will function properly, it is necessary that the elastic, when applied, be under tension. Then when the tension is removed from the elastic, it has a tendency to gather the cloth to which it is sewn to produce the desired result.

At the present time in order to properly tension the elastic when being sewed to cloth, there is provided an elastic tensioner. The elastic tensioner is in the form of a pair of clamp plates which are urged together by means of a spring under the desired tension. The elastic tensioner works perfectly as long as the sewing operation is taking place. However, if for any reason it is necessary to stop the sewing machine at a point during the application of the elastic, there is a tendency for the elastic to creep through the elastic tensioner and as a result a portion of the garment has sewn therein elastic which is. not tensioned and therefore which does not function. Such garments must then be sold as seconds. This, of course, is undesirable inasmuch as a much lesser ,price is obtained for seconds.

It is therefore the primary object of this invention to provide an elastic tensioner which is so constructed that when the sewing machine of which it is a part is in operation, the elastic is fed therethrough under the desired tension and at the same time as soon as the sewing machine is stopped, the elastic is clamped so as to prevent lcreeping of the elastic and thereby eliminating the usual application of an elastic not tensioned.

Another object of this invention is ,to provide an improved elastic tensioner for sewing machines, the elastic tensioner including a pair of clamp plates which are disposed in opposed relation and urged together by means =of a spring whereby resistance to movement of elastic between the clamp plates is facilitated, the pressure there- :sliding movement of elastic between the clamp plates, .and there being provided a device for further applying pressure to the clamp plates sufficient to completely eliminate the sliding of the elastic between the clamp plates when desired.

A further object of this invention is to provide a holdling unit for elastic tensioners, the holding unit being in .the form of a pressure applying device which will in- -crease the pressure between clamp plates of an elastic tensioner to completely prevent the sliding of elastic therethrough, the holding unit being provided with-controls operated in response to the disengagement of actuating controls for an associated sewing machine whereby when a sewing operation is stopped, the holding unit will automatically operate to apply an increased pressure :and thereby positively prevent the sliding movement of elastic between the clamp plates of the elastic tensioner.

will become subsequently apparent reside in; the details of construction and operation as more fully hereinafter described and claimed, reference being had to the aceorn: panying drawing forming a part hereof, wherein like numerals refer to like parts throughout, and in which;

Figure 1 is a fragmentary perspective view of a sewing machine which has mounted thereon an elastic tensioner employing the holding unit which is the subject of this invention;

Figure 2 is an enlarged fragmentary vertical sectional view taken upon an enlarged scale through the elastic tensioner and the holding unit; and

Figure 3 is a diagrammatic view of the controls for the holding unit.

Referring now to the drawings in detail, it will be seen that there is illustrated in Figure 1, an industrial sewing machine of a conventional type, the sewing machine being referred to in general by .the reference numeral 10. In order that elastic tape 12 may be applied under tension by the sewing machine 10, there is provided a support 14 which extends up through the sewing machine 10, the support being tubular and having extending at generally right angles thereto a shaft 16. Mounted on the shaft 16 for rotation is a reel 18 for the elastic tape 12. The reel 18 is releasably retained on the shaft 16 by means of a collar 20.

In order to facilitate the application of the elastic tape, 12 under tension, there is also provided an elastic tensioner which is referred to in general by the reference 32 has releasably threadedly engaged thereon a nut 34.

- .by applied being insufiicient to completely prevent the Carried by the bolt 30 above the threaded portion 32 is a fixed clamp plate 36. The fixed clamp plate 36 is suitably permanently secured to the bolt 30.

Slidably mounted on the bolt 30 and encasing the upper portion thereof is a sleeve member 38. The sleeve member 38 has secured to the underside thereof for movement therewith a movable clamp plate 40 which opposes the clamp plate 36.

The upper end of the bolt 30 is in the form of a reduced externally threaded portion 42 on which there is adjustably engaged a stop member 44. The stop member 44 engages the upper end of a spring 46 which surrounds the bolt 30 and which engages the lower end of the member 38. The upper part of the member 38 is open at its sides as at 48, as is best shown in Figure 1, to facilitate the adjustment of the member 44 to vary the spring pressure on the movable clamp plate 40.

The belt 30 is provided with a rectangular opening 50 therethrough intermediate the clamp plates 36 and 40.

v The tape 12 being applied is threaded through the open- These togetherwith other objects and advantages which ing 50 and is resiliently compressively engaged by the clamp plates 36 and 40 so as to resist the movement of the tape 12 through the bolt 30.

In the normal operation of the sewing machine 10,

as material is being sewed and the elastic tape 12 is being applied, resistance of the tape 12 between the clamp plates 36 and 40 results in the pre-tensioning of the tape 12 so that when sewed to fabric (not shown) and released, the tape will automatically gather on the fabric. HOW-2 ever, when the operation of the sewing machine 10 is:

3 the sewing machine and the elastic tensioner 22 is released.

In order to prevent the releasing of the elastic tape 12 when thesewing machine 10 is not in operation, there is provided a holding unit which is referred, to in general by the reference numeral 52. The holding unit 52 includes an electromagnetic device 54 of the type which includes a coil 56 and a solenoid 58, the solenoid 58 terminating in its lower end in a plunger 60 aligned with the member 38. The upper end of the member 3 5 is provided with a pad 62 to absorb the shock of the plunger 60 when the electromagentic device S i is actuated.

The electromagnetic device 54 includes a mounting plate 63. The mounting plate 63 is secured in place by means of suitable fasteners 64 to one of which there is connected a spring66 which is engaged with the upper end 68 of the core 58. The spring 66 results in the automatic return of the core 58 to the inoperative position shown in Figure 2.

In order to facilitate the mounting of the holding unit 52, there is provided an L-shaped bracket 70. The L- shaped bracket 70 includes a horizontal flange 72 and an upstanding flange 74. The flange 72 is clamped against the clamp 28 by the bolt 30, the fixed clamp plate 36 and the nut 34. The fasteners 64 aroused to secure the mounting bracket 63 to the upright flange 74.

As is best shown in Figure 3, the electromagnetic device 54 includes a pair of lead wires 76 and 78 which may be connected to any convenient power source, including the power source for the sewing machine 10. The opposite ends of the coil 56 are connected'to the lead wires 76 and 78. The lead wires 76 and 78 have mounted therein a switch 80 which is of the normally closed type and which is urged towards a closed position by means of a spring 82. p

Illustrated in cooperation with the switch 89 is a pedal 84 which is a part of the actuating control for the sewing machine 10.- Although a pedal has been illus-.

trated, any type of control which is used for the sewing machine 10 will suflice. A suitable link 86 extends between the pedal 84 and the switch 80 so as to operate the switch 80 when the pedal 84- is operated. The pedal 84 is shown in a partially depressed position and the switch 80 open. This is the normal operating position for the operation of the sewing machine 10. When the pedal 84 is released, the switch 80 will automatically return to its nonnally closed position at which time the holding unit 52 will be actuated. When the holding unit 52 is actuated, the plunger 60 engages the cushion pad 62 which in turn forces the clamp plate 40 downwardly towards the clamp plate 36 so as increase the pressure exerted on the elastic tape 12. The pressure will be sufiicient to prevent the movement of the elastic tape 12 between the clamp plates 36 and 40.

From the foregoing, it will be seen that there has been devised a highly desirable holding unit for elastic tensioners which will automatically set the elastic tensioners when the operation of the sewing machine is stopped. The holding unit is of such a nature whereby it may be readily mounted on existing elastic tensioner installations.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is'claimed as new is as follows:

1. Incornbination with a sewing machine of the type having actuating controls, an elastic tensioner for tensioning elastic as it is being applied while using said sewing machine, and means cooperating with said elastic tensioner for automatically actuating said elastic e ioner 4 to apply an increased force to said tensioner whereby to hold elastic against movement through said tensioner in response to the releasing of said actuating control to stop the operation of said sewing machine, whereby creeping of elastic being sewn is prevented through the tensioner when the sewing machine is not in operation.

2. In combination with a sewing machine of the type having actuating controls, an elastic tensioner for tensioning elastic as it is being applied while using said sewing machine, and means cooperating with said elastic tensioner for automatically actuating said elastic tensioner to apply an increased force to said tensioner whereby to hold elastic against movement through said tensioner in response to the releasing of said actuating control to stop the operation of said sewing machine, whereby creeping of elastic being sewn is prevented through the tensioner when the sewing machine is not in operation, said means including an electromagnetic device of the type having a plunger engageable with said tensioner for applying an increased force thereto.

3. In combination with a sewing machine of the type having actuating controls, an elastic tensioner for tensioning elastic as it is being applied while using said sewing machine, and means cooperating with said elastic tensioner for automatically actuating said elastic tensioner to apply an increased force to said tensioner whereby to hold elastic against movement through said tensioner in response to the releasing of said actuating control to stop the operation of said sewing machine, whereby creeping of elastic being sewn is prevented through the tensioner when the sewing machine is not in operation, said means including an electromagnetic device of the type having a plunger engageable with said tensioner for applying an increased force thereto, said elastic tensioner having a buffer aligned and engaged by said plunger when said electromagnetic device is actuated.

4. In combination with a sewing machine of the type having actuating controls, an elastic sensioner for tensioning elastic as it is being applied while using said sewing machine, and means cooperating with said elastic tensioner for automatically actua ing said elastic tensioner to apply an increased force to said tensioner whereby to hold elastic against movement through said tensioner in response to the releasing of said actuating control to stop the operation of said sewing machine, whereby creeping of elastic being sewn is prevented through the tensioner when the sewing machine is not in operation, said means including an electromagnetic device of the type having a plunger engageable with said tensioner for applying an increased force thereto, an electric circuit for said electromagnetic device including a control switch, said control switch being operated by said actuating controls.

5. In combination with a sewing machine of the type having actuating controls, an elastic tensioner for tensioning elastic as it is being applied while using said sewing machine, and means cooperating with said elastic tensioner for automatically actuating said elastic tensioner to apply an increased force to said tensioner whereby to hold elastic against movement through said tensioner in response to the releasing of said actuating control to stop the operation of said sewing machine, whereby creeping of elastic being sewn is prevented through the tensioner when the sewing machine is not in operation, said means including an electromagnetic device of the type having a plunger engageable with said tensioner for applying an increased force thereto, said electromagnetic device including a mounting bracket, said mounting bracket being secured in place by said elastic tensioner.

References Cited in the file of this patent UNITED STATES PATENTS 2,231,648 Weis Feb. ll, 194-1 2,582,211 Turner Ian. 8, 1952 2,683,439 Soldo July 13, 1954 

